Combination type electrical switch



NOV. 25, 1941. Aw ER 2,264,042

COMBINATION TYPE ELECTRICAL SWITCH Filed March 18, 1939 2 Sheets-Sheet 1 Nov. 25, 1941.

COMBINATION TYPE ELECTRICAL SWITCH v Filed Mai-ch 18, 19:59 2 Sheets-Sheet 2 1NVENTOR5 J. A. LAWLER EIAL 2,264,042

Patented Nov. 2 5, 1941 COMBINATION TYPE ELECTRICAL SWITCH Jack A. Lawler, Montoursville, Pa., and Frank 0.

Best, Detroit, Mich.

Application March 18, 1939, s rial No. 262,626

9 Claims.

The present invention relates to a new and useful combination type electrical switch particularly intended for use in operating doorbells, but with many other useful adaptations.

Heretofore, householders have been annoyed by itinerant agents, peddlers, salesmen, etc., ringing the doorbell and intruding upon the privacy of the home.

An object of the present invention is to prevent undesirable callers from ringing the doorbell without inconveniencing legitimate callers. This is effected by requiring the caller to press certain combinations of buttons, preferably designated with letters, to operate the doorbell.

A further object of this invention is to prevent callers who do not know the tenants name from operating the doorbell. This is effected by adjusting the switch so that it will operate the doorbell only when buttons, preferably those corresponding to the first two letters of the tenants last name are depressed. V

A further object of this invention comprehends the provision of a simple circuit breaking arrangement so that if more than the proper buttons are depressed the circuit is opened and the bell will not operate. This arrangement includes connecting all contacts, for all of the buttons, in series.

Another object of this invention is to provide a method for preventing detection of the proper buttons (either by sight or feel) by maintaining all the buttons at the same height (when the switch is not being operated) and by maintaining substantially uniform spring pressure and travel on the live and "dead buttons.

Another obj eat of the invention is to provide an external adjustment, so that the switch can be set for various button combinations without disassembling the vunit or changing the wiring.

Another object of the invention is to provide an adjustment for setting the button combination which automatically controls the circuit breaking system.

Another object of the invention is to provide an adjustment which can be set from the back of the switch so that proper spacing of the contacts can be accurately determined by the number of turns of the adjusting screw, without using gages.

Another object of the invention is to provide night illumination of the instruction plate and buttons by a small hooded bulb, controlled by a spring returned switch, constructed and so located that it will not be confused with the bell operating means, and the circuit for the switch and light operating over the conventional wiring system, with no changes in the latter.

A further object of the invention includes parts arrangement which makes possible slim, modemistic styling of the. entire switch, and also contributes to ease of manufacture-with a minimum of intricate parts.

The above and other objects of the invention will'appear from the following description and appended claims when considered in connection with the accompanyingdrawings forming a part of this specification in which like reference characters designate corresponding parts in the several views.

In said drawings:

Figure 1 is a front view of the device showing the light control, instruction plate, and button arrangement.

Figure 2 is a vertical staggered section taken on line 2-2 of Fig. 3 showing the light and the mechanism of the control switches.

Figure 3 is a vertical section taken on line 3-3 of Fig. 2 showing'the light and the mechanism of the control switches. V

Figure 4 is a rear view showing the electrical connections and adjusting mechanism.

Figure 5 is a horizontal section on line 55 of Fig. 2, illustrating the adjustment before setting for the desired letter combination.

Figure 6 is a typical horizontal section illustrating how the circuit is broken if a dead button is depressed.

Figure 7 is a typical horizontal section illustrating the adjustment of a live button.

Figure 8 is a typical horizontal section illustrating how the circuit is closed when a live button is pushed.

. Figure 9 is a wiring diagram illustrating a typical setting of the combination. I

Before explaining in detail the present'in'vention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings; since the invention is capable of other embodiments and of being practiced or carried out in various ways; Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it 1s not intended to limit the invention claimed herein beyond the requirements of the prior art.

As seen in the drawings, construction and operation of the preferred embodiment is ,as fol-'- ows:

Amolded plastic housing I retains all a the presence of unsightly mounting screws and the styling is clean and unbroken. At its lower end;

the housing I is provided with ascrew boss 'l-for the lower attaching screw 3.which has a hollowhexagon head 8 for driving purposes, requiring a special wrench for installation and removal,

thus minimizing the possibility of -th'e f t or -tampering.

In the rear interior of the housing I and secured by screws 91s a fibenplat'e ifl 'onthe rear surface of which arerhountedbrass 'electrical connector bars. II secured. inplaceby rivets 'I2 and having at their .ends tapped holes I3'provided with splits I 4, the spring action'of. which insuresa tight gripon'the contact screws 15, thus preventing lost motion androtation' of the latter after adjustment. 'In manufacturing assembly, these contact. screws I5 areadju'sted by-a screwdriver at the slotted ends lfiuntil'apredetermined clearancefexists "between the rearsides of the contactscrewheads I8 and thefront face of the fiberplateifli Across. each'pair'of oppositely disposed contact screws I5 is'installed a contact bridge I9 positioned in'vertical and lateral alignment by openings 25 'in housing], the ends of which bridge :areof hooked form, and the termination of each end being disposed between the rear side. I! of the contacts'crew head'I8 and front surface of-the fiber plate" I0. Pins 2| pressed into thefiber pIate IO- locate coil springs 2,2,which exert pressure betweenthe front face of the fiberplate I0 and-the rear surfaces 23 of the contact bridges I9 thus normally maintaining the front surfaces 24 of'the terminations 20 of the contactbridges lii in positive contact with the rear sides I! of the contact screwheads I8. It will be observed"that.--the"-opposite1y disposed rows of connector bars I I on the rear surface of, the fiberplate I0. are arranged instaggered formation in order that the connectorsl I, the contact screws I5 and the contact bridges l9 will cooperatively form 'series arranged components ofan electrical circuit when desired; as shownin'Figure 9.

In the front face of housingl are rectangular openings 26 through which projectpush-buttons 2. the latter being provided with holes 29 to receive very light coil springs'30, the ends of the latter resting on the front surfaces 3| of'the contact bridges; I9 and the springs 30' acting to force the push buttons 21 outward, this movementbeing limited by the flanges 28 of thefor rner when corningto rest on the inside surface 32 ofthe front of the housing I. By the use of thesprings- 30 the buttons 27 are all maintained leveland this feature combined" with the spring pressure reaction when the'buttons are pushed servesto maintain uniform appearance and feel of live. and dead buttons, th s minimizing thej'ri'sk. of anunauthorized persons succeeding in detecting the pre-selec ted buttons utilized for operation oftheidoor-bell.

Due toth'e'man'ufacturing assembly adjustment fl contest screws 15.. aa redetermined space will exist between the rear surfaces 33 of the buttons 21 and the front surfaces 3| of the contact bridges I9. This space is for clearance purposes in order to insure positive contact between the contact bridge I9 and the contact screws I5, when the former is pushed forwards by springs 22. Figure 5 illustrates the positions of the various parts related to each pair of oppositely disposed contact screws I5 after final assembly. It will be noted that electrical contact has been made between contact bridge I9 and both contact screws I5.

"Figure '7 illustrates the positions of the various parts-related to a pair of oppositely disposed 15.

contact screws I5 .a fter one of these screws has been adjusted in'or'der to permit the control but- "ton 21in front of it to be active in closing an electrical circuit when pushed.

It will be observed that the rear face I1 of the contact screw head I8 'has been moved outward sufficiently from' the front :surface 24 or thei'contact; bridge termination 20 to break".electriqalvcontact.atcthis point. The force of: spring 22 'hasw overcome; that of the very light .spring :30. -and:hasforc.ed,;one end of the contact'bridge forwardtoiwhere its outside surface 3i contacts'the inside ledge :34 of thecase I. This abutment.assuresaapositive relation between the rear surface 23 of. thewcone tact bridge!!! and the front surfacea35. of :the contact screw I 5- in order that; travel? and clear; ance at this. point may beheld to. 'con'stantiidie' mensions. Figurei8..illustrate show contact is made in an electricalcirc'uit.when?aiipreselected button utilized for the operation of the-device is pushed. Pressureonbutt'on 21:pushes.;one end of the contact. bridgerearwardly where its 'rear surface 23 contacts the front surface-.ofxthetade justing'screw head'I'B.

Figure ,6 illustrates the :re'sult. of mushingea button not preselectedfor theoperation off-the device. It will be noted'thatpressure on; the u ton 2 pushes one end ofthecontacti bridge is rearwardly thus 'brealging thecontact' between he rom; face 4- of; he ontact b id e. terminal? i n 8. nd the ear face Llof; theeccntactscrew h e 8.- Th prevc ts h nQssi 'Htvofanauthor zed. er on pr ssin al ois he ut on at the same time in order to defeat the purpos g i d v s Fi u i lu ira ee ewiri ediaera wherein the connector bars it, ,the adj u sting screws} I5 and the contact. bridgesl i a-all .cg-oper-j atively formseries arranged comperrents of electrical circuit includinga source of; electrical energy' 'in this case a .transfo en-QQ; an electrically operated device in this cascadoor bell 31, when the prepara ions are plished simultaneously. "In the "illustrationI contact screws I 5, shownlightly, shaded;- arelnone'ffc tive in. the operation ofthe deviceand-ar'e. n contact, while'those shown inblack. areQDre selected andja renormally. out, of contact. Terese:

i s hef uttons:associated;with.thev latter. contall screws simultaneously, closes the circuit arid device is e n p ration I miehtb noted djwith a s epwise? are also e mimher Q ii. .SQT dr s specific applications. For the. purpose housing: I. The switch M is operated by a lever M andpull chain 45and remains in contact only when the chain 45 is held down. As access to the bulb and switch unit is only from the rear of the housing I, theft of the bulb is prevented. The bulb 39 and switch 4| are shown in Figure 9 in series'and are in parallel with the terminals 9 of the combination control unit. When the switch 4| is closed, the bulb 39 isthen in series with the transformer 36 and the bell 31. The combined high electrical resistance of the bulb 39 and the magnet coil of the bell 31 will allow a small amount of current to flow through the bulb filament for illumination, but the current fiow will be insufficient to operate the bell. By this method, additional wiring is not required when replacing the conventional door bell switch with this device.

From the drawings and the foregoing description it will be readily apparent that when this device is utilized in connection with a doorbell that the buttons will be designated with letters of the alphabet and that a person desiring to ring said bell must push buttons preferably corresponding to the first two letters of the tenants last name simultaneously in order to obtain results. Thus much annoyance and inconvenience is spared the tenant, while at the same time legitimate callers are not put to any inconvenience. It will also be observed that if a person tries to push the right buttons by pushing a group of or all of the buttons the circuit is automatically broken and his attempts to ring the bell are frustrated. Because of the mechanism employed, it will be observed that detection of the proper buttons by sight or feel will be improbable. It will also be seen that the device can be set for any name without dismantling the unit or changing the wiring and that the circuit breaking contacts are automatically controlled by the position of the adjusting screws.

It will also be readily apparent to one experienced in the art that the use of this device need not be restricted to doorbell control alone, and that there are numerous applications of the device to meet conditions where combination control is desirable. It is also possible to use the contact mechanism in other forms of electrical switch and control mechanisms where combination control is not necessary.

We claim:

1. In an electrical switch, a movable contact with spaced surfaces, a normally stationary contact with a portion extending between the surfaces of the movable contact, a spring forcing the movable contact in one direction to establish electrical contact between one surface of the movable contact and the said portion of the stationary contact, means limiting the travel of the movable contact when moved by the spring, and means to adjust the stationary adjustable contact to a position out of normal electrical contact with the movable contact.

2. In an electrical switch, the combination of a pair of electrical conductors, spaced adjustable contact screws associated with each conductor, flanged heads on said contact screws, a movable electrical conductor with opposed hook shaped ends, said hooks partially enclosing the flanges of the adjustable contact screws, spring means for maintaining contact between the movable electrical conductor and the flanged heads of the contact screws, and push button means for breaking said contact.

3. In an electrical switch, a housing having a wall, a pair of electrical conductors secured to said wall and'securing adjustable contact screws having flanged heads spaced from said wall,'a movable contact with opposedhooked ends, said hooked ends enclosing the flanges of the contact screws, spring means biasing said movable contact in one direction, push buttons at each end of the movable contact to move it against said spring means, and a spring between each end of the movable contactand its button.

I 4. In an electrical-combination type switch, a plurality of switches connected in series, each including a movable contact, a normally fixed contact and adjusting means to position said normally fixed contact so that its switch is normally open or normally closed, a mounting for said adjusting means, push buttons mounted upon and restrained for limited movement by said mounting, and spring means between said push buttons and said movable contacts to force said push buttons out to the full extent of their limited movement.

5. In an electrical combination type switch, a housing, an electrically insulating structure associated with said housing, spaced electrical conductors arranged in oppositely disposed staggered rows on said structure and secured thereto, normally stationary contact in said housing and associated with the ends of said electrical conductors, said contacts being adjustable, for a normally open or closed circuit position, cooperating movable contacts in said housing and selectively engaging oppositely disposed adjustable contacts to connect them in series, push buttons on said housing each designated by identification means and substantially in line with each movable contact to actuate it.

6. In an electric switch, a first switch element having two spaced contact surfaces, a second and cooperating switch element having a contact portion between said two surfaces, one of said elements being movable in a direction transverse to said surfaces, stop means to limit the movement of said movable element in either direction, and the other element being adjustable to either of two normally fixed positions, one in which the normally engaged elements are separated to open the switch upon movement of said movable element and the other in which the normally disengaged elements are engaged to close the switch upon the same movement of the said movable element.

7. An electric switch unit comprising a closed casing, means to open or close an electric circuit therein, means projecting into said casing manually movable in one direction to actuate said 1 first means, and means including an adjustably movable member. projecting into said casing to adjust said first means so that the circuit will be either opened or closed upon the one direction of manual movement of said second means.

8. A readily installable combination type switch unit comprising a closed casing having a back and a front and adapted to be fixedly secured with its back against a wall or the like so that its back is inaccessible after installation, electric terminals on its back, a plurality of adjustable switches in said casing connected in series between said terminals, certain preselected normally open switches being closed on actuation and the remaining normally closed switches being opened upon actuation, manually operable means with suitable indicia on the front of said casing and extending therein to selectively actuate each of said switches, and means including a plurality of adjustably movable members on 4 apes-n42 a single iipifight row of; movable contact memhens, each contact member having two laterally extending ends positioned behind the two .buttons of a pair of buttons and being movably mounted so that the two ends thereof may be actuated independently by the two buttons of the corresponding pair, and a plurality of normally fixed contact members positioned withone to cooperate with each end of each movable 19 c ontact member.

JACK LAWLER. FRANK o. BEST. 

